Dry flowable agricultural compositions of glyphosate and sulfonylurea herbicides made without drying of the final product

ABSTRACT

A dry flowable agricultural composition made by mixing glyphosate and an anhydrous base salt with a sulfonylurea herbicide and stabilizer (sodium metasilicate or sodium carbonate), all of which is combined a heat activated binder without using a drying step.

This application has been filed under 35 U.S.C. 371 from theinternational application PCT/U.S.93/05370 (WO 93/25081).

This application has been filed under 35 U.S.C. 371 from theinternational application PCT/U.S.93/05370 (WO 93/25081).

The present invention comprises a dry flowable agricultural compositionof N-(phosphonomethyl)glycine (defined hereinafter as glyphosate) withand without a sulfonylurea herbicide and processes for the preparationof the composition without a drying step.

WO91/13546 discloses the preparation of dry flowable agriculturalcompositions comprising an active ingredient, binder and chemicalstabilizer. Among the active ingredients disclosed are varioussulfonylureas and N-(phosphonomethyl)glycine (glyphosate) with adisclosure that one or more may be used.

While generally useful for granulation without drying, WO91/13546 wouldnot be useful for processing wetcake glyphosate or wet glyphosate saltwithout treatment according to the present invention.

WO90/07275 describes the preparation of glyphosate compositions orglyphosate salt granule compositions containing liquid surfactants. Theability to utilize a co-herbicide in the compositions is disclosed, andseveral sulfonylurea herbicides, including metsulfuron methyl, arespecifically named.

The processes of the prior art have the disadvantage of requiring adrying step at some stage of production of the formulations disclosedand because the final products contain environmentally-sensitivechemicals such as sulfonylureas and other potentially volatilecomponents, large and expensive air-purification systems are necessaryin drying operations to prevent untoward chemical release.

SUMMARY OF THE INVENTION

The compositions of the invention are dry flowable agriculturalcompositions comprising glyphosate or glyphosate salt with asulfonylurea. The process of the invention produces a free flowinggranular composition without a drying step by heating. The resultinggranules can also be described as free flowing, non-caking, lowattrition glyphosate compositions.

A process for the preparation of a dry flowable agriculturally suitablecomposition whose pH when measured by a 1% by weight aqueous solution ofthe composition is 4 or higher which comprises a process selected fromprocess A and process B, said process A comprising

(a) blending the following ingredients

(1) 1-70% wet glyphosate or wet glyphosate salt,

(2) 0.1-40% of an anhydrous base salt,

(3) 0-10% of an anti-caking agent, and

(4) 0-1% of an anti-foaming agent to form a mixture I,

(b) milling mixture I to form a powder,

(c) blending the powder with 5-30% of a heat activated binder,

(d) heating to 60°-70° C., and

(e) cooling to 50° C. or lower, and said process B comprising

(f) blending 0.1-40% of an anhydrous base salt with 1-70% wet glyphosateor wet glyphosate salt to form a blended mixture I,

(g) adding to the blended mixture under blending conditions thefollowing ingredients

(1) 0-10% of an anti-caking agent,

(2) 0-1% of an anti-foaming agent,

(3) 0-20% of a stabilizer,

(4) 0-40% of a sulfonylurea herbicide to form blended mixture II,

(h) milling blended mixture II to form a powder,

(i) blending mixtures I and II with 5-30% of a heat activated binder,

(j) heating to 60°-70° C., and

(k) cooling to 50° C. or lower

wherein all of the above percentages are by weight based on thecomposition provided when a sulfonylurea is present the stabilizer is0.1-20%.

The process of the invention is more advantageous when the glyphosate isa wetcake. Most preferably, the process of the invention is by processB. However, the process of the invention can also be carried out withglyphosate that has been previously dried because even when using dryglyphosate the resulting composition using some prior art methods wouldrequire drying. The processes of the invention do not require drying ofthe composition made from dry or from wet glyphosate. Preferably, theprocess of the invention is carried out with the presence of asulfonylurea herbicide and stabilizer, but it also can be carried outwithout a sulfonylurea herbicide and without a stabilizer.

Another embodiment of the invention is a free flowing, non-caking, lowattrition agriculturally suitable glyphosate composition comprising inweight percent based on the total composition weight

(1) 1-70% previously dried or wetcake glyphosate or a wet glyphosatesalt,

(2) 0-15% water,

(3) 0.1-40% anhydrous base salt,

(4) 0-10% anti-caking agent,

(5) 0-1% anti-foaming agent,

(6) 0.1-20% stabilizer,

(7) 5-30% heat activated binder, and

(8) 0.1-40% sulfonylurea herbicide

provided that the pH of a 1% aqueous solution of the composition ishigher than or equal to 4.

A preferred composition comprises, in weight precent based on totalformulation weight, the above composition comprising:

(1) 20-60% of the glyphosate or glyphosate salt,

(2) 2-8% water,

(3) 4-30% anhydrous base salt,

(4) 0-5% anti-caking agent,

(5) 0-1% anti-foaming agent,

(6) 2-15% stabilizer,

(7) 10-25% heat-activated binder, and

(8) 0.5-20% sulfonylurea herbicide

provided that the pH of a 1% aqueous solution of final product isgreater than or equal to 4.

Anhydrous base salts in the compositions may convert free water tocrystalline waters of hydration.

When a glyphosate salt is used, the preferred cation is sodium.

A preferred composition is that in which the base salt is an anhydroussodium salt.

In addition, a preferred composition comprises a stabilizer which issodium metasilicate.

A preferred binder is one selected from the class consisting of ethyleneoxide/propylene oxide copolymer, polyethoxylated dinonylphenol,polyethylene glycol and mixtures of the foregoing.

Both glyphosate and the sulfonylureas hereinafter described are knownherbicides.

What is meant by glyphosate is N-(phosphonomethyl)glycine of thestructural formula ##STR1##

The preferred sulfonylurea herbicides are methyl2-[[[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]-carbonyl]amino]sulfonyl]benzoate(metsulfuron methyl) and methyl2-[[[[(4,6-dimethyl-2-pyrimidinyl)amino]-carbonyl]amino]sulfonyl]benzoate.

DETAILED DESCRIPTION OF THE INVENTION

Conventional methods for preparing products containing glyphosateherbicide involve drying steps to remove water with heat at one or morestages of production. "Wetcake" glyphosate, so named because it cancontain 2-20% water (typically 7-12% water) is obtained after processingof technical glyphosate acid. Prior to this invention, no granules ofglyphosate prepared from "wetcake" glyphosate without a drying stepwere:

1) stable to chemically sensitive mixing partners such as sulfonylureaherbicides in the compositions,

2) non-caking and non-dusty, and

3) rapidly dissolving in water.

In the prior art, even sulfonylurea/glyphosate compositions preparedfrom dry glyphosate have required drying of the final product. Nowaccording to the present invention drying for either situation is notnecessary.

The instant invention comprises a novel composition and a novel processfor preparing dry flowable compositions of glyphosate which do notrequire drying steps at any stage in the preparation. What is meant bydrying is subjecting to heat or other means for the purpose of removingwater. The sulfonylureas in the novel compositions of this invention donot decompose in the presence of the water because the water is believedto exist as crystalline water of hydration of the base salt, and thus isinocuous. The compositions of the instant invention are alsofree-flowing, non-caking, low attrition granules. Prior art granulesmade without a drying step are soft compositions without a stablestructure.

The process of the instant invention is advantageous over knownprocesses that require a drying step because fine particles or dust ofenvironmentally-sensitive pesticides and other potentially volatilecomponents may be released to the environment in the drying step. Knownprocess conditions include large, expensive air-purification systemswhich are required to clean the large volumes of forced air required indrying operations at manufacturing facilities. The present inventionprecludes the need of such equipment.

Various salts are known to effect glyphosate activity and are routinelyadded to enhance weed control (e.g., see Nalewaja and Matysiak in WeedScience, 1991, 39, 622). Another advantage of the present invention isthat the base salts known to enhance biological efficacy are alreadypresent and therefore need not be tank-mixed at the time of application.

A third advantage is that the binder present in the compositions of thepresent invention enhances the activity of the glyphosate. Normally,surfactants are tank-mixed with glyphosate to obtain a comparableimprovement in efficacy and their use in tank-mixing is not necessaryfor the present compositions.

The nature of the glyphosate herbicide incorporated into thecompositions can be acid "wetcake", dry acid, or a wet salt of the acid.When "wetcake" glyphosate, dry glyphosate or wet salt is used, ananhydrous base salt is added to make the glyphosate acid or saltcomposition of the invention which is a

1) dry, free-flowing and millable to a fine powder,

2) inert to decomposition of a sulfonylurea mixed with the glyphosate inthe composition, and

3) available for direct processing to finished granules without a dryingstep.

For example, the granular composition of the invention prepared by themethod exemplified in Example 1 below

1) show no change in metsulfuron methyl content after one week at 54°C.,

2) dissolve in water in less than two minutes as measured in theBreak-up test,

3) have less than 5% attrition, and

4) are non-caking, as determined by the Collaborative InternationalPesticide Analytical Council (CIPAC) test.

The stabilizer is not required in the process of the invention whenglyphosate or its salt is the only active ingredient.

However, when dry glyphosate acid, wetcake glyphosate acid, or wetglyphosate salt are used in mixtures with sulfonylureas, then the weightpercent of the stabilizer is greater than zero. Even "dry" glyphosateforms when mixed with the various components of processes of the priorart require drying. However, the compositions of this invention and theprocess of the invention do not require any drying step whether thestarting glyphosate is wet or dry or whether a sulfonylurea is presentor absent.

Useful anhydrous base salts are those which have hydrated forms withmelting points above 60° C. Useful anhydrous base salts have cationsthat include ammonium, lithium, potassium, sodium, and polyvalentcations as that part of the salt with carbonate, carbonate/phosphateblends, citrate, metaborate, metasilicate, pyrophosphate, sulfate andtetraborate, as well as others. Ammonium salts are less desirablebecause of the problem of evolving ammonia. Potassium salts are lessdesirable because of the problem of forming hygroscopic compositions.Lithium salts are useful but can be more expensive than thecorresponding sodium salt. Polyvalent cationic salts are useful but candeactivate glyphosate. Therefore, sodium base salts are preferred.

The use of anhydrous base salts that have hydrated forms with meltingpoints less than 60° C. are ineffective in the compositions of thepresent invention with "wetcake". The sulfonylurea in the compositiondecomposes to such an extent that ineffective herbicidal formulationsresult. Anhydrous disodium phosphate has a hydrated form with a meltingpoint below 60° C. When disodium phosphate was used instead of sodiumpyrophosphate in Example 1 below, the components formed a solid masswhich was inoperable as an agricultural formulation. However, disodiumphosphate is effective in compositions with dry glyphosate acid asillustrated in Example 13 below.

Useful examples of anti-caking and anti-foaming agents are 10X sugar,Soap L®(i.e., sodium stearate) and other materials well-known to thosein the art.

Suitable stabilizers comprise metal carbonate salts, metal acetatesalts, or metal metasilicate salts which protect the sulfonylurea fromdecomposition in the formulation. The metal salts comprise divalent andmonovalent metals.

Metal carbonate or metal metasilicate salts are used when glyphosatewetcake or wet glyphosate salt is used. Sodium carbonate or sodiummetasilicate are preferred. When Example 1 below was repeated withoutsodium carbonate as the stabilizer, a 33% decomposition of metsulfuronmethyl was observed after 1 week at 54° C. Similarly, when sodiumacetate was used instead of sodium carbonate, 30% decomposition of thesulfonylurea was observed. When Example 12 was repeated without sodiumcarbonate as the stabilizer utilizing additional anhydrous base saltthere was a 30% loss of metsulfuron methyl after two weeks at 54° C.

In addition to metal carbonates and metal metasilicates, metal acetatesalts, preferably sodium acetate, may be used as stabilizers when dryglyphosate acid is used. As indicated in Example 14 hereinafter, whensodium acetate was used instead of sodium pyrophosphate (the anhydrousbase) and sodium carbonate, <5% decomposition of metsulfuron methyl wasobserved after two weeks at 54° C.

The term "heat-activated binder" refers to any surface active materialcomprised of one or more components which dissolve rapidly in water,have sufficient viscosity near the melting point for tackiness, and arethus capable of acting as a binder when heat is applied. At someelevated temperature, the binder softens and melts, thereby becomingsticky enough to bind the pesticidal particles into granules. Apreferred amount of binder used in this invention is 10-25% by weightbased on the total weight of the composition. Suitable heat-activatedbinders include any component or mixture of components meeting the fivecriteria listed below. The binder must:

(1) have a melting point range within 40°-120° C., and preferably45°-100° C.;

(2) have a hydrophile/lipophile balance (HLB) of about 14 or greater;

(3) dissolve in mildly-agitated water in 60 min. or less, preferably 50min. or less;

(4) have a melt viscosity of at least 200 centipoise (cps); preferably1000 cps or greater, and most preferred 2000 cps or greater; and

(5) have a difference of 5° C., and preferably 3° C. or less between thesoftening point and onset of solidification.

Examples of suitable heat-activated binders, which are not intended tobe limiting, are ethylene oxide/propylene oxide copolymers such asPluronic® F108, polyethoxylated dinonylphenol such as Macol® DNP150,polyethylene glycols such as PEG 8000.

A "sulfonylurea herbicide" can be any one of the entire class ofherbicides containing the following structural moiety, and any closelyrelated chemical functionalities. ##STR2##

Preferred are compositions wherein the sulfonylurea herbicide is acompound of the formula ##STR3## wherein: J is ##STR4## R is H or CH₃ ;R¹ is F, Cl, Br, NO₂, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₃ -C₄ cycloalkyl,C₂ -C₄ haloalkenyl, C₁ -C₄ alkoxy, C₁ -C₄ haloalkoxy, C₂ -C₄alkoxyalkoxy, CO₂ R¹², C(O) NR¹³ R¹⁴, SO₂ NR¹⁵ R¹⁶, S(O)_(n) R¹⁷,C(O)R¹⁸, CH₂ CN or L;

R² is H, F, Cl, Br, CN, CH₃, OCH₃, SCH₃, CF₃ or OCF₂ H;

R³ is Cl, NO₂, CO₂ CH₃, CO₂ CH₂ CH₃, SO₂ N(CH₃)₂, SO₂ CH₃, SO₂ CH₂ CH₃,OCH₃, or OCH₂ CH₃ ; R⁴ is C₁ -C₃ alkyl, C₁ -C₂ haloalkyl, C₁ -C₂ alkoxy,C₂ -C₄ haloalkenyl F, Cl, Br, NO₂, CO₂ R¹², C(O)NR¹³ R¹⁴, SO₂ NR¹⁵ R¹⁶,S(O)_(n) R¹⁷, C(O)R¹⁸ or L;

R⁵ is H, F, Cl, Br or CH₃ ;

R⁶ is C₁ -C₃ alkyl, C₁ -C₂ alkoxy, C₂ -C₄ haloalkenyl, F, Cl, Br, CO₂R¹², C(O) NR¹³ R¹⁴, SO₂ NR¹⁵ R¹⁶, S(O)_(n) R¹⁷, C(O) R¹⁸ or L;

R⁷ is H, F, Cl, CH₃ or CF3;

R⁸ is H, C₁ -C₃ alkyl or pyridyl;

R⁹ is C₁ -C₃ alkyl, C₁ -C₂ alkoxy, F, Cl, Br, NO₂, CO₂ R¹², SO₂ NR¹⁵R¹⁶, S(O)_(n) R¹⁷, OCF₂ H, C(O)R¹⁸, C₂ -C₄ haloalkenyl or L;

R¹⁰ is H, Cl, F, Br, C₁ -C₃ alkyl or C₁ -C₂ alkoxy;

R¹¹ is H, C₁ -C₃ alkyl, C₁ -C₂ alkoxy, C₂ -C₄ haloalkenyl, F, Cl, Br,CO₂ R¹², C(O)NR¹³ R¹⁴, SO₂ NR¹⁵ R¹⁶, S(O)_(n) R¹⁷, C(O)R¹⁸ or L;

R¹² is C₁ -C₃ alkyl optionally substituted by halogen, C₁ -C₂ alkoxy orCN, allyl or propargyl;

R¹³ is H, C₁ -C₃ alkyl or C₁ -C₂ alkoxy;

R¹⁴ is C₁ -C₂ alkyl;

R¹⁵ is H, C₁ -C₃ alkyl, C₁ -C₂ alkoxy, allyl or cyclopropyl;

R¹⁶ is H or C₁ -C₃ alkyl;

R¹⁷ is C₁ -C₃ alkyl, C₁ -C₃ haloalkyl, allyl or propargyl;

R¹⁸ is C₁ -C₄ alkyl, C₁ -C₄ haloalkyl or C₃ -C₅ cycloalkyl optionallysubstituted by halogen;

n is 0, 1 or 2;

L is ##STR5## R_(j) is H or C₁ -C₃ alkyl; W is O or S;

X is H, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, C₁ -C₄ haloalkoxy, C₁ -C₄haloalkyl, C₁ -C₄ haloalkylthio, C₁ -C₄ alkylthio, halogen, C₂ -C₅alkoxyalkyl, C₂ -C₅ alkoxyalkoxy, amino, C₁ -C₃ alkylamino or di (C₁ -C₃alkyl) amino;

Y is H, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, C₁ -C₄ haloalkoxy, C₁ -C₄alkylthio, C₁ -C₄ haloalkylthio, C₂ -C₅ alkoxyalkyl, C₂ -C₅alkoxyalkoxy, amino, C₁ -C₃ alkylamino, di(C₁ -C₃ alkyl )amino, C₃ -C₄alkenyloxy, C₃ -C₄ alkynyloxy, C₂ -C₅ alkylthioalkyl, C₂ -C₅alkylsulfinylalkyl, C₂ -C₅ alkylsulfonylalkyl, C₁ -C₄ haloalkyl, C₂ -C₄alkynyl, C₃ -C₅ cycloalkyl, azido or cyano;

z is CH or N;

and their agriculturally suitable salts;

provided that:

(a) when X and/or Y is C₁ haloalkoxy, then Z is CH;

(b) when X is halogen, then Z is CH and Y is OCH₃, OCH₂ CH₃, N(OCH₃)CH₃,NHCH₃, N(CH₃)₂ or OCF2H.

Even more preferred are compositions wherein the sulfonylurea isselected from the group:

2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]benzenesulfonamide(chlorsulfuron);

methyl 2- [[[[(4,6-dimethyl-2-pyrimidinyl)amino]-carbonyl]amino]sulfonyl]benzoate (sulfometuron methyl);

ethyl2-[[[[(4-chloro-6-methoxy-2-pyrimidinyl)-amino]carbonyl]amino]sulfonyl]benzoate(chlorimuron ethyl);

methyl 2-[[[[(4-methoxy-6-methyl-1,3, 5-triazin-2yl)amino]carbonyl]amino]sulfonyl]benzoate (metsulfuron methyl);

methyl 2-[[[[(4,6-dimethoxy-2-pyrimidinyl) amino]carbonyl]amino]sulfonyl]-6-(trifluoromethyl) -3-pyridinecarboxylate;

methyl 2- [[[[[4-ethoxy-6- (methylamino) -1,3,5-triazin-2-yl]amino]carbonyl]amino]sulfonyl]-benzoate;

2-(2-chloroethoxy) -N- [[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]benzenesulfonamide (triasulfuron);

ethyl5-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]-carbonyl]amino]sulfonyl]-1-methyl-1H-pyrazole-4-carboxylate;

N-[[(4,6-dimethoxy-2-pyrimidinylamino]carbonyl]-3-(ethylsulfonyl)-2-pyridinesulfonamide;

methyl3-[[[[(4-methoxy-6-methyl-l,1,3,5-triazin-2-yl)amino]carbonyl]amino]sulfonyl]-2-thiophenecarboxylate;

methyl 2-[[[[N-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)-N-methylamino]carbonyl]amino]sulfonyl]benzoate(tribenuron methyl); methyl 2-[[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]-carbonyl]amino]sulfonyl]methyl ]benzoate (bensulfuron methyl );

N- [[(4,6-dimethoxy-2-pyrimidinyl) -amino]carbonyl]-1-methyl-4 -(2-methyl-2H-tetrazol-5-yl ) - 1H-pyrazole-5-sulfonamide;

methyl 2-[[[[[4-(dimethylamino)-6- (2,2,2-trifluoroethoxy)- 1,3,5-triazin-2-yl]amino]-carbonyl ]amino]sulfonyl ]-3-methylbenzoate;

2-[[[[(4,6-dimethoxy-2 -pyrimidinyl) amino]-carbonyl]amino]sulfonyl]-N,N-dimethyl-3-pyridinecarboxamide (nicosulfuron); and

methyl2-[[[[[4,6-bis(difluoromethoxy)-2-pyrimidinyl]amino]carbonyl]amino]sulfonyl]benzoate.

One skilled in the art can select dyes, humectants, spreading agents,corrosion inhibitors, fillers, stickers, odorants, bitterants or otherformulation ingredients to obtain some special properties and still bewithin the scope of this invention.

A process for preparing the compositions is described in the instantinvention. The process comprises first blending the glyphosate with ananhydrous base salt. All other components except the binder are thenadded and the mixture is milled to a powder. The powder is combined witha binder in a V-blender, and then tumbled and heated to about 60°-70° C.The granules are then cooled to about 50° C. or lower and collected.

The preferred process is that in which the glyphosate is in the form ofa wetcake.

A particular preferred composition of the invention as described aboveincludes a sulfonylurea selected from the group consisting ofchlorsulfuron; sulfometuron methyl; chlorimuron ethyl; metsulfuronmethyl; tribenuron methyl; bensulfuron methyl; nicosulfuron;triasulfuron; methyl 2-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]-6-(trifluoromethyl)-3-pyridinecarboxylate;methyl2-[[[[[4-ethoxy-6-(methylamino)-1,3,5-triazin-2-yl]-amino]carbonyl]amino]sulfonyl]benzoate;ethyl5-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]-sulfonyl]-1-methyl-1H-pyrazole-4-carboxylate;N-[[(4,6-dimethoxy-2-pyrimidinylamino]carbonyl]-3-(ethyl-sulfonyl)-2-pyridinesulfonamide;N-[[(4;6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-1-methyl-4-(2-methyl-2H-tetrazol-5-yl)-1H-pyrazole-5-sulfonamide;and methyl2-[[[[[4-(dimethylamino)-6-(2,2,2-trifluoroethoxy)-1,3,5-triazin-2-yl]amino]carbonyl]amino]sulfonyl]-3-methylbenzoate.

The heating step in the process is not a drying step but an activationof the binder. No weight loss (e.g., through water loss) was observedwhen a blender containing wetcake glyphosate and the other ingredientsof the compositions of this invention was weighed before and after heatactivation. A drying step in a typical formulation process requireslonger heating times, higher temperatures, and a forced air system toremove the water vapor and other volatiles. As indicated above, theforced air must be purified to prevent contamination of the environment,and these purification systems are large and expensive. No suchpurification systems are required in the heat activation step in theprocess of the present invention.

The fact that the final composition weight equals the sum of the weightsof the components suggests that the anhydrous base salt converts freewater from glyphosate wetcake to crystalline waters of hydration. Watersof hydration are not removed in the heat activated granulation step, donot decompose sulfonylureas, and do not facilitate reaction ofglyphosate with the stabilizer. If free water were present and sodiumcarbonate was the stabilizer, glyphosate would react with the sodiumcarbonate to liberate carbon dioxide and the sulfonylurea woulddecompose. No weight loss occurred during heat activated granulation andthe sulfonylureas remained stable. Therefore our hypothesis is that thebase salt reacts with free water to form water of hydration.

In the Examples below, the abbreviation "a.e." is defined as acidequivalents. The abbreviation "rh" is defined as round hole. Thepercentages indicated are by weight.

Noncaking was measured by the CIPAC test which is described in MT 172"Flowability of Water Dispersible Granules after Heat Test UnderPressure". The Attrition test measures the stability of the granules tobreak down under dry conditions. The granules of the present inventionexhibit low attrition as determined by the Attrition test in U.S. Pat.No. 3,920,442. A sample of the granules to be tested are separated intosize fractions first by sieving of granules passing a 10 mesh screen sothe largest aggregate in any fraction has a diameter no more than 1.4times larger than the smallest granule in the fraction. For example, inthe fraction isolated between 10 and 14 mesh sieves, the largestaggregate has a diameter of approximately 2 mm and the smallestaggregate has a diameter slightly larger than 74 microns. Other suitablesieve fractions can be isolated, for example, between 25 and 35 meshsieves, 30 and 40 mesh sieves, 100 and 140 mesh sieves, etc. A threegram sample from the isolated size fraction is placed in a 0.24 literglass jar, 60 mm outer diameter by 54 mm inner diameter by 100 mm long,fitted with a screw cap. One hundred and twenty 0.64 cm diameter andfourteen 1.3 cm diameter steel balls are added to the jar, the jar iscapped and is then placed in a rotating device such as a jar roller androtated around its longitudinal axis at 25-26 RPM for exactly twominutes.

The jar is removed from the roller, its contents discharged carefully toprevent further grinding of the remaining aggregates onto a nest of U.S.Standard sieves, consisting of a No. 10 sieve to remove the balls and asieve in which the sieve opening is equal to the diameter of thesmallest aggregates in the original sample, and a pan. The stackedsieves are gently rotated to separate the steel balls from the sample.The No. 10 sieve is then removed and the screening of the sample on theother sieve continued with rotation and tapping, until all the fines arecollected in the pan. The fine material in the pan is weighed, and theweight percent of mechanical breakdown of the aggregates is calculated:##EQU1## Attrition values of less than 40%, and preferably less than30%, are acceptable.

The Break-up test measures the time it takes for the granules to form adispersion in water or dissolve in water. A 0.5 sample of granules isadded to a 100 mL graduated cylinder (internal height after stopperingis 22.5 cm, inner diameter is 28 mm) containing 90 mL of distilled waterat 25° C. and the cylinder clamped in the center, stoppered and rotatedabout the center at 8 RPM until the sample is completely broken up inthe water. The time for break up is measured. The granules of theinvention should break up in less than 5 minutes, preferably less than 3minutes.

EXAMPLE 1

A mixture of 45.88 g of "wetcake" glyphosate (11% water, 86.3% a.e.) and31.67 g of anhydrous sodium pyrophosphate as blended in a Black andDecker Handy Chopper® mill for 10 minutes, and hammer-milled through a0.02 rh screen. All other components except the binder, i.e., 1.10 g of10X sugar, 0.55 g of Soap L®, 1.16 g of metsulfuron methyl and 9.85 g ofsodium carbonate, were hammer-milled through a 0.02 rh screen.

The milled glyphosate/base salt mixture and milled powders were blendedtogether for 5 minutes, combined with 19.8 g of Pluronic® F108 (<40mesh), an ethylene oxide/propylene oxide block polymer with 80% ethyleneoxide and 20% propylene oxide units, in a V-blender, tumbled as thetemperature of the powders were brought to 70° C. with a hair dryer,cooled to 50° C. and the granules collected.

They dissolved in water in less than 2 minutes as measured by theBreak-up test. Less than 5% attrition was observed in the Attritiontest, and the granules were non-caking (CIPAC test). The granulesobtained showed no decomposition of the metsulfuron methyl after 1 weekat 54° C.

Examples 2-6 indicate that different binders or binder mixtures can beused.

EXAMPLE 2

Example 1 was repeated using 45.88 g of glyphosate (11% water, 86.3%a.e.), 25.08 g of anhydrous sodium pyrophosphate, 1.10 g of 10X sugar,0.55 g of Soap L®, 1.15 g of metsulfuron methyl (95%), 9.85 g of sodiumcarbonate and 26.40 g of Macol®DNP 150 (20/80 mesh), a polyethylateddinonylphenol with 150 ethylene oxide units made by Mazer Chemicals. Thegranules dissolved in 90 seconds.

EXAMPLE 3

Example 2 was repeated using PEG Carbowax® 8000 (20/80 mesh) instead ofMacol® . DNP 150. The granules dissolved in 30 seconds.

EXAMPLE 4

Example 2 was repeated using Pluronic® F108/disodium phosphate 4/1(20/80 mesh) instead of Macol® DNP 150. The mixture was prepared bymelting and mixing the components together, grinding the solids with alaboratory mill and collecting the 20/80 mesh fraction. The granulesdissolved in 285 seconds.

EXAMPLE 5

Example 2 was repeated using Pluronic® F108/Siponate® DS10 (4/1 mixture,20/80 mesh) instead of Macol® DNP 150. The mixture was prepared bymelting and mixing the components together, grinding the solids with alaboratory mill and collecting the 20/80 mesh fraction. The granulesdissolved in 135 seconds.

EXAMPLE 6

Example 2 was repeated using Pluronic® F108 (20/80 mesh) instead ofMacol® DNP 150. The granules dissolved in 255 seconds.

Examples 7-10 show that the binder size can be regulated to affect therate at which the granules dissolve in water.

EXAMPLE 7

Example 2 was repeated using Pluronic® F108 (20/70 mesh) instead of20/80 mesh. The granules dissolved in 280 seconds.

EXAMPLE 8

Example 2 was repeated using Pluronic® F108 (30/70 mesh) instead of20/80 mesh. The granules dissolved in 190 seconds.

EXAMPLE 9

Example 2 was repeated using Pluronic® F108 (40/60 mesh) instead of20/80 mesh. The granules dissolved in 135 seconds.

EXAMPLE 10

Example 2 was repeated using Pluronic® F108 (40/70 mesh) instead of20/80 mesh. The granules dissolved in 120 seconds.

EXAMPLE 11

This Example shows that a portion of the anhydrous base salt can bereplaced with additional metsulfuron methyl, and that additionalingredients may be added.

Example 1 was repeated using 45.88 g of glyphosate (11% water, 86.3%a.e.), 14.25 g of anhydrous sodium pyrophosphate, 1.10 g of 10 sugar,0.55 g of Soap L® (sodium stearate), 11.00 g of Lomar® PW (a dispersingagent comprising a condensed naphthalene sulfonate), 1.10 g of Wessalon®50S (a precipitated silica filler/carrier), 3.43 g of metsulfuron methyl(95%), 10.69 g of sodium carbonate and 22.00 g of Macol® DNP 150 (<20mesh). The Lomar® PW and Wessalon® 50S were combined with the sugar,Soap L®, metsulfuron methyl and sodium carbonate.

The granules obtained showed no decomposition of the metsulfuron methylafter 1 week at 54° C. They were dispersed in water in less than 2minutes by the Break-up test. Less than 5% attrition was observed in theAttrition test, and the granules were non-caking (CIPAC test).

Examples 12-15 illustrate that the dry acid form of glyphosate may beused to produce granules without drying of the final products. In thesecases, anhydrous bases for which the hydrated forms melt below 60° C.may be added. Stabilizers are required.

EXAMPLE 12

A mixture of 40.82 g of glyphosate acid (97% a.e.), 34.53 g of sodiumpyrophosphate, 1.10 g of 10X sugar and 0.55 g of Soap L® were blended ina Black and Decker Handy Chopper® mill for 10 minutes, and hammer-milledthrough a 0.02 rh screen. 1.16 g of metsulfuron methyl and 9.85 g ofsodium carbonate were similarly blended for 10 minutes, andhammer-milled through a 0.02 rh screen. The two milled mixtures werecombined and treated with 22.00 g of Pluronic® F108 (<20 mesh) in aV-blender, tumbled as the temperature of the powders were brought to 70°C. with a hair dryer, cooled to 50° C. and the granules collected.

A <5% loss of metsulfuron methyl was observed after 2 weeks at 54° C.

EXAMPLE 13

Example 12 was repeated using disodium phosphate instead of sodiumpyrophosphate. A <5% loss of metsulfuron methyl was observed after 2weeks at 54° C.

EXAMPLE 14

Example 12 was repeated using 44.38 g of sodium acetate instead ofsodium pyrophosphate and sodium carbonate. A <5% loss of metsulfuronmethyl was observed after 2 weeks at 54° C.

EXAMPLE 15

Example 12 was repeated using 44.38 g of sodium carbonate instead ofsodium pyrophosphate. A <5% loss of metsulfuron methyl was observedafter 2 weeks at 54° C.

EXAMPLE 16

A mixture of 46.48 g of "wetcake" glyphosate (11% water, 86.3% a.e.) and32.08 g of anhydrous sodium pyrophosphate as blended in a Black andDecker Handy Chopper® mill for 10 minutes, and hammer-milled through a0.02 rh screen. All other components except the binder, i.e., 1.11 g of10×sugar, 0.56 g of Soap L® and 9.85 g of sodium carbonate, werehammer-milled through a 0.02 rh screen. The milled glyphosate/base saltmixture and milled powders were blended together for 5 minutes, combinedwith 19.8 g of Pluronic® F108 (<40 mesh), an ethylene oxide/propyleneoxide block polymer with 80% ethylene oxide and 20%propylene oxideunits, in a V-blender, tumbled as the temperature of the powders werebrought to 70° C. with a hair dryer, cooled to 50° C. and the granulescollected.

The granules dissolved in water in less than 2 minutes as measured bythe Break-up test. Less than 5% attrition was observed in the Attritiontest, and the granules were non-caking (CIPAC test).

EXAMPLE 17

Example 1 was repeated using 9.85 g of sodium metasilicate instead ofsodium carbonate. The granules obtained showed no decomposition of themetsulfuron methyl after two weeks at 54° C.

EXAMPLE 18

Example 2 was repeated using 9.85 g of sodium metasilicate instead ofsodium carbonate, and PEG Carbowax® 8000 (20/80 mesh) instead of Macol®DNP 150. The granules obtained showed no decomposition of themetsulfuron methyl after two weeks at 54° C.

What is claimed is:
 1. A process for the preparation of a dry flowableagriculturally suitable composition whose pH when measured by a 1% byweight aqueous solution of the composition is 4 or higher comprising(a)blending 0.1-40% of an anhydrous base salt with 1-70% wetcake glyphosateto form a blended mixture I, (b) blending the following ingredients(1)0-10% Of an anti-caking agent, (2) 0-1% of an anti-foaming agent, (3)0.1-20% of a stabilizer selected from sodium metasilicate and sodiumcarbonate, (4) 0.1-40% of a sulfonylurea herbicide to form blendedmixture II, (c) milling blended mixture II to form a powder, (d)blending mixtures I and II with 5-30% of a heat activated binder, (e)heating to 60°-70° C., and (f) cooling to 50° C. or lower wherein all ofthe above percentages are by weight based on the composition.
 2. Theprocess of claim 1 wherein the sulfonylurea herbicide is 0.5-20%.
 3. Afree flowing, non-caking, low attrition agriculturally suitableglyphosate composition comprising in weight percent based on the totalcomposition weight(1) 1-70% wetcake glyphosate, (2) 2-8% water, (3)0.1-40% anhydrous base salt, (4) 0-10% anti-caking agent, (5) 0-1%anti-foaming agent, (6) 0.1-20% stabilizer selected from sodiummetasilicate and sodium carbonate, (7) 5-30% heat activated binder, and(8) 0.1-40% sulfonylurea herbicide provided that the pH of a 1% aqueoussolution of the composition is higher than or equal to
 4. 4. Thecomposition of claim 3 wherein the wetcake is 20-60%, the anhydrous basesalt is 4-30%, the anti-caking agent is 0-5%, the stabilizer is 2-15%,the heat activated binder is 10-25% and the sulfonylurea herbicide is0.5-20%.
 5. The composition of claim 3 wherein the anhydrous base saltis a sodium salt.
 6. The composition of claim 3 wherein the sulfonylureaherbicide is methyl 2-[[[[(4-methoxy-6-menthyl-1,3,5-triazin-2-yl)amino]carbonyl]amino]-sulfonyl]benzoate.
 7. The composition of claim 3wherein the sulfonylurea herbicide is methyl2[[[[(4,6dimethyl-2-pyrimidinyl)amino]carbonyl]amino ]sulfonyl]benzoate.
 8. The composition of claim 3 wherein the sulfonylureaherbicide is nicosulfuron.
 9. The composition of claim 4 wherein thesulfonylurea herbicide is selected from chlorsulfuron; chlorimuronethyl; tribenuron methyl; bensulfuron methyl; methyl2-[[[[(4,6-dimethoxy-2-pyrimidinyl)-amino]carbonyl]amino]sulfonyl]-6-(trifluoromethyl)-3pyridinecarboxylate;methyl 2-[[[[[4-ethoxy-6-(methylamino)- 1,3,5 -triazin -2 -yl ]amino]carbonyl ]amino ]sulfonyl]benzoate;2-(2-chloroethoxy)-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl )amino]carbonyl ]benzenesulfonamide; ethyl5-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]-carbonyl]amino]sulfonyl]-1-methyl-1H-pyrazole-4-carboxylate;N-[[(4,6-dimethoxy-2-[pyrimidinylamino]-carbonyl]-3-(ethylsulfonyl)-2-pyridinesulfonamide;N-[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-l-methyl-4-(2-methyl-2H-tetrazol-5-yl)-1H-pyrazole-5sulfonamide;and methyl2-[[[[[4-(dimethylamino)-6-(2,2,2-trifluoroethoxy)-1,3,5-triazin-2-yl]amino]-carbonyl]amino]sulfonyl]-3-methylbenzoate.